Zeller R, Duboule D
European Molecular Biology Laboratory, Heidelberg, Germany.
Bioessays. 1997 Jul;19(7):541-6. doi: 10.1002/bies.950190703.
Molecular and developmental studies of limb pattern formation have recently gained widespread attention. The fact that vertebrate limbs are amenable to both genetic and embryological manipulations has established this model system as a valuable paradigm for studying vertebrate development. Limb buds are polarised along all three major axes and the establishment of the dorso-ventral (DV) polarity is dependent upon cues localised in the trunk, where a DV ectodermal interface is produced by confrontation of dorsal and ventral identities. By analogy to Drosophila imaginal disc development, this interface has been proposed to determine and position an ectodermal organising centre, the Apical Ectodermal Ridge (AER), controlling limb bud outgrowth. Recent fate mapping studies and studies of genes regulating DV limb polarity, AER formation and differentiation suggest, however, that DV patterning and AER induction, though coordinately regulated during limb bud outgrowth, may early on be more dissociated than expected.
肢体模式形成的分子和发育研究最近受到了广泛关注。脊椎动物的肢体适合进行基因和胚胎学操作，这一事实使这个模型系统成为研究脊椎动物发育的宝贵范例。肢芽沿所有三个主要轴极化，背腹（DV）极性的建立依赖于躯干中定位的线索，在躯干中，背侧和腹侧身份的对抗产生了DV外胚层界面。通过类比果蝇成虫盘发育，有人提出这个界面可以确定并定位一个外胚层组织中心，即顶端外胚层嵴（AER），它控制着肢芽的生长。然而，最近的命运图谱研究以及调节DV肢体极性、AER形成和分化的基因研究表明，尽管在肢芽生长过程中DV模式形成和AER诱导是协同调节的，但在早期可能比预期的更不相关。
